Be sure you to anneal copper head-gasket to make it soft before installing.
Sure better safe than sorry with rich mixtures to start. Then dial back to 12.5:1 under boost for max-power with dyno-tuning or wideband.
Setting wastegate spring too weak can cause problems with low-boost and dropping boost as RPMs increase. That’s because even with controller holding solenoid fully-closed full time (zero pressure to diaphragm), wastegate will still be pushed open by exhaust pressure itself. You’ll want to set spring for lowest boost you’ll ever run with pressure line directly connected to wastegate. A lot of turbos are configured with hose connected directly from compressor-outlet to wastegate diaphragm. Then select spring to give lowest boost you want to run, say 10psi.
Then insert boost-solenoid between compressor-outlet and diaphragm. EBC will give this minimum boost at 100% on solenoid (passthrough). Once this spring-rate is set, EBC then can be programmed for higher boost-levels (such as 15-20psi). If your EBC has ability, you can program different boost-levels per gear as traction-control. Set whatever boost barely spins 1st, then higher for 2nd. Max-boost can be used for 3rd gear onwards.
You’ll want to look into higher-pressure valve springs to prevent valve-float under max-boost at higher RPMs. General rule-of-thumb is 2% more pressure per 1psi boost. So if you’re gonna run 10psi max, you’ll want 20% stiffer valve-springs. Max-boost of 20psi will need 40% stiffer springs.